Red Light therapy has gained attention in recent years, highlighted by social media and its alleged ability to produce anti-aging effects. Is this indeed true, or is this technology being utilised better in other areas of science?
Within the visible region of the electromagnetic spectrum, red light has the longest wavelength of 620 to 750 nm. Due to these longer wavelengths, red light can penetrate the skin and is subsequently able to be absorbed by respiratory chain components. Therefore, red light can be beneficial in aspects of healing wounds, repairing tissues and rejuvenating skin.
Throughout history, natural sunlight has been utilised as a treatment for mental and physical health issues – this has been known as Hilotherapy.
From this, several scientific discoveries paved the way for red light therapy used today. These include the light spectrum by Isaac Newton, the invention of the lightbulb by Thomas Edison and discovery of light as therapy by Niels Ryberg.
Further, in 1893, Dr. Finsen, a Danish physician, used artificial light for the first time in UV light therapy; he received the Nobel Prize for Medicine in 1903 for using UV light to treat tuberculosis! However, this was still the beginning. These initial treatments could only target a very small area at a time, resulting in treatment that took several hours daily.
The evolution of the use of light for medicinal uses only then expanded further in 1920s and 30s when it became known that vitamin D is essential for good health and that vitamin D production can be stimulated from exposure to the sun’s UV light. In addition, UV light has been shown to have positive effects on the body just through exposure! Known as bright light therapy, UV lamps have been used to target emotional issues and other ailments such as psoriasis, eczema and fungal infections.
With the invention of low-level laser therapy devices, light therapy became even more popular ; it became part of dermatological and surgical treatments particularly for skin cancer. These devices allowed light to be more concentrated without the destructive effects of high-level hot lasers. LEDs followed – these are able to produce a single wavelength of light instead of the multitude of wavelengths incandescent light bulbs often produce. Despite the range of colours in the visible spectrum LED devices can express, the only wavelengths of light shown to have effects on the body are those that show red or blue coloured lights.
Therapeutically red light has been used to treat issues such as high bilirubin in infants, chronic pain management, neurological diseases, hair restoration and chronic skin disorders. Research has attributed the therapeutic effects of red light on healing due to its ability to enhance cell energy production. Other studies observed beneficial effects to sleep quality and cognitive function.
A study conducted in 2017 confirmed that red light therapy had anti-inflammatory effects. Perhaps even more excitingly, Dr. Michael Hamblin , a leading doctor at the forefront of red light therapy has outlined that applying red light to the thymus may stimulate the body’s ability to fight off cancer, however it should not be applied to the tumor itself. Furthermore, there has been a recent buzz into studies that have found that Repeated Low-Level Red-Light (RLRL) therapy can be used to slow childhood myopia – also known as nearsightedness. Myopia is often characterised by an increase in the axial length of the eyeball which can be due to environmental or hereditary roots. It is already known that bright light exposure from increased time outdoors can prevent or delay myopia development and following research results, red light has been shown to be more efficient than any other wavelengths to slow this development. Although there have been no short-term side effects, long-term effects are still to be investigated. This is an exciting discovery as children’s eyesights are deteriorating with 1 in 3 children being nearsighted; this has been seen especially after the covid lockdowns where children spent more time on screens and less time outdoors.
Red light therapy technology has a wide variety of uses as well as medicine, spanning multiple areas of science. For example, NASA experimented with red light therapy in the mid-1990s with an aim to grow plants in space! They used red lights which were small, safe and produced low heat – it was difficult to use regular grow lights which used a lot of power and heat. During this process NASA scientists working under these lights found that abrasions on their hands were healing faster than normal, suggesting that red light also has a healing effect on the skin.
In zero gravity conditions also, the bone and muscle mass of individuals experience a great loss and show much slower healing. Through research it was identified that these problems resulted from poor cell growth due to the zero-gravity conditions. Red light therapy was used to remedy this issue through stimulating cellular metabolism allowing muscle mass and bone density to be regained while in space. Red lights have continued to be used as grow lights on earth.
Not only does the medical and agricultural sectors benefit from red light therapy but, perhaps also elucidated from media attention, so does the beauty industry. Lately, red light therapy has gained popularity due to its believed ability to result in a younger appearance: its anti-aging properties. A randomized controlled trial that aimed to determine the efficacy of red light therapy for skin healing, including reducing the appearance of fine lines and skin wrinkles, supports this use! They found that the use of red light increased collagen density of those participants of the trials which they measured ultrasonographically and an appreciable improvement in skin complexion.
Unlike other techniques of skin rejuvenation, red light therapy alters cellular function using low-level, non-thermal LED light. This is known as photobiomodulation (PBM) or low-level light therapy (LLLT).
The application of red light has been shown to be safe, non-invasive and have multiple benefits to the body therapeutically, as well as ‘anti-aging’ the skin! It is very possible that we may begin to see the popularity of red-light devices increasing further as they become commonplace in the home, therapy and beauty.
Written by Colleen He, a 2nd year Medicinal and Biological Chemistry student at The University of Edinburgh, and Secretary for EUSci.
Edited by Emma Walsh, a 2nd year Neuroscience student as The University of Edinburgh, and EUSci Online News Editor.
References:
Helmenstine, Anne Marie, Ph.D. “The Visible Spectrum: Wavelengths and Colors.” ThoughtCo, Apr. 5, 2023, link: https://www.thoughtco.com/understand-the-visible-spectrum-608329
M. Youssef, A. Shehata, A. Adly, et al., ‘Efficacy of Repeated Low-Level Red Light (RLRL) therapy on myopia outcomes in children: a systematic review and meta-analysis’, BMC Ophthalmology, Feb. 20th, 2024, link: https://bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-024-03337-5
‘THE HISTORY OF RED LIGHT THERAPY’, Platinum led therapy lights, Dec., 2022, link: https://platinumtherapylights.com/en-gb/blogs/news/the-history-of-red-light-therapy
P. Roxby, ‘One in three children short-sighted, study suggests’, BBC News, Sept. 25th, 2024,link: https://www.bbc.co.uk/news/articles/c0m099zm4wyo
Wunsch, Alexander, Matuschka, Karsten, ‘A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase’, Pubmed, Nov. 28, 2013, link: https://pubmed.ncbi.nlm.nih.gov/24286286/#:~:text=A%20controlled%20trial%20to%20determine%20the%20efficacy%20of,wrinkles%2C%20skin%20roughness%2C%20and%20intradermal%20collagen%20density%20increase
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